1. Field of the Invention.
The present invention relates to remote controls for operating electronic devices, and more particularly to universal remote controls which can be programmed by a user to operate one of a plurality of different types of electronic devices produced by different manufacturers.
2. Related Art.
Universal remote controls are well known devices which can be programmed by a user to operate one of a plurality of different types of electronic devices produced by different manufacturers. Universal remote controls are often used to control audio/video equipment, such as TVs, VCRs, CD players and the like. Due to their programmability, consumers frequently use universal remote controls to replace lost remote controls and as a single control device for controlling a number of separate audio/video components.
Typically, a universal remote control is programmed by entering a reference code associated with an electronic device to be controlled into a memory device of the universal remote control. The reference code identifies, the electronic device type and manufacturer and allows the universal remote control to transmit control signals having the proper signal structure to the device to be controlled. The proper signal structure is determined by characteristics which include, but are not limited to, carrier frequency, pulse width, pulse modulation and overall timing.
Several methods are available for entering a reference code into a universal remote control. One method is the direct, manual entry method. In such a method, a list of reference codes for a variety of popular device models is included in the printed instruction set that accompanies the universal remote control. The user finds the reference code associated with the device to be controlled and manually enters the code numbers using a numeric keypad disposed on the universal remote control. This method can be problematic for the user because the specific code numbers must be known in order to program the universal remote control. Thus, the reference code list must be kept nearby and consulted each time the code must be reentered or a new code needs to be entered.
Another method of entering a reference code is a semiautomatic automatic code search method in which the user steps through a plurality of reference codes stored in the universal remote control until the desired code is found. In this method, the user steps through the set of stored reference codes one at a time by pressing a designated control button, sends a control signal after each step and observes whether the device reacts in the desired manner, i.e., power ON/OFF. When the device reacts to the signal in the expected manner, the user knows that the correct reference code has been identified and uses another keystroke sequence, for example, an ENTER button, to terminate the code search and store that reference code into the memory device of the remote control. A difficulty with this method is that the user may be forced to go through a large number of steps, and therefore keystroke combinations, before finding the correct reference code because there may be a large number of reference code possibilities. Also, even though this method will determine and store the desired reference code, the user does not know the specific reference code numbers. Thus, if the reference code is stored in volatile memory and power is lost or if the user wishes to program another universal remote for the same device, the user must repeat the same code search sequence.
Another method of entering and storing a reference number is an automatic code searching method wherein the universal remote control automatically cycles through a list of reference codes and sends a control signal to the device for each reference code when a user initiates a code search sequence. When the device reacts to the control signal in the desired manner, the user terminates the code search sequence, for example, by pressing or releasing a designated button, thereby storing the correct reference code into the universal remote control. Again, the reference code is automatically stored into the remote control and the user does not know the reference code numbers.
As noted above, it may be desirable for a user to know the reference code numbers in the event that the user needs to reprogram the remote control or wishes to program other remote controls to operate the same device. However, it may be difficult to determine the reference code numbers after the reference code has been programmed into the remote control using the automatic or semi-automatic programming methods described above.
One code identification method allows a user to determine the code numbers by counting a blinking sequence on a set of LEDs and matching the count sequence with a reference table in a printed instruction set. However, this method becomes inconvenient if the blinking sequence occurs too quickly and the user is forced to repeat the process several times in order to obtain the correct count sequence. Further, this method still requires the user to refer to a printed list.